The field of the present invention relates to small-sized vehicles such as motorcycles, motor tricycles and the like.
In the above-referred small-sized vehicles, normally there is provided a fairing for covering a front portion of a vehicle body over its front surface as well as its both left and right side surfaces. And in a vehicle provided with such fairing rear view or, back-mirrors are mounted at the upper side portions of the fairing via arm members projecting from the side portions as disclosed for example, in Japanese Utility Model Publication No. 60-17429. Also, in Laid-Open Japanese Patent Specification No. 58-49538 is disclosed a back-mirror device which is constructed in such manner that when on external load is applied thereto it may turn to avoid the external load. In these back-mirror devices, the above-mentioned arm member becomes thick and has a large wind pressure area because it must rigidly support the back-mirror so as not to induce rocking or vibration, and moreover, as it project to the side of the vehicle body, an air resistance upon running of the vehicle would be increased by this arm member.
A back-mirror device having a structure in which the arm member is made of two parts taking into consideration an aerodynamic characteristic, is known by Laid-Open Japanese Patent Specification No. 59-32534. In this back-mirror device, an arm member for supporting a mirror is formed of two thin arm portions. However, this cannot fully prevent vibration of a mirror resulted from running of a vehicle.